Double throw clamp-tight switch



May 15, 1951 A. s. cAswELL 2,553,238

DOUBLE THRow CLAMP-TIGHT swITcx-x ATTRIVEKS May 15,'1951 Filed May 21,1946 4 Sheets-Sheet 2 41 42 43 Os e@ INVENTOR.

Awibur S. Caswell BY Wwf-h ATTORNEYS' May 15, 1951 A. s. cAswELl.2,553,238

DOUBLE THROW CLAMP-TIGHT SWITCH Filed May 2l, 1946 4 Sheets-Sheet 5INVENTOR. Awrbuw S. Caswell Y www@ ATTORNEYS A. S. CASWELL DOUBLE THROWCLAMP-TIGHT SWITCH May 15, 1951 4 sheets-sheet 4 Filed May 2l, 1946INVENTOR. 'Arbmo S.Caswe|l muy;

ATTORNEYS' Patented May 1`5, 1951 DQUBLE THROW CLAMP-TIGHT'SWITCHArthur' S. Caswell, Philadelphia', Pa., assignor t0 I. T. E.Circuit-Breaker Company, Philadelphia, Pa., a corporation ofPennsylvania Application May 21, 1946, Serial No. 671,172

2-Claims. l

My present invention relates toswitchgear, and more particularly todouble throw switchgear varranged to engage the movable contact with thestationary'contacts in a tightf clamping arrangement in each position oftheA double throw switch.

Heretoforel in switchgear of the knife switch type, it has beencustomary to provide a clamping arrangement for interengaging themovable element of the knife `switch with the stationary contact. Aportion ofthe closing movement of the switch was used to bring themovable contact -orb1ade up into registry with ther-stationary Contactand the remainingV movement of the switch handle performed the clampingaction. This4 type of clamping actionv is shown in the Scott Patent2,246,072, assigned to the assignee of the present invention.

However, the problem becomes more complex in double throw switches wherethe movable contact blade has a neutral position as well as two separatecontactingv positions 180 apart.

Various means have been attempted torprovide for Aadequate clampingpressure at bothcontacting positions of the knife blade but these haveresulted in extremely complex duplicate clamping mechanisms or inhavinga clamped contact arrangement at one position only with the otherposition being subjected to` only light clamping engagement.

In general, my invention contemplates-an arrangement of a double throwclamp tight switch in which partial movement of the operating handle rstthrows the movable contact into position for engagement with one of theterminals. On furthermovement of the operating handle to its nalposition, a wedge member is operated which clamps the movablecontactinto engagement with its associated terminal. This same operationoccurs at the' opposite terminal, the wedging member again functioningtoclamp the contact in engagement.

My invention' specifically contemplatesV the utilization of a wedgemember so arranged that on operation ofthe knife switch handle to theclosed position in either direction, the wedge will be actuatedr todrive the bridging blades together.

Accordingly an object of my invention is to provideV a noVelclamp tightarrangement for a double throw knife switch.

A further object of my inventionis to provide a novel wedging mechanismfor effectingclamping of a double throw knife switch in either of itspositions.

(C1. 2ML-170) 2 Still another object of my invention is 'to provide anarrangement whereby the knife switch bladezisoperable duringone portionof the movement of the operating handle to engaging posiy tion and isoperated into clampingy engagement by the remaining operation of thehandle;

The foregoing and many other objects of my invention will becomeapparent in the following description and drawingsy in which:

Figure 1 is a side view of my novel double throw knifeswitch.

Figure 2 is a view inperspective` of. my novel double throw knife switchshowing the` wedging element therein.

Figure 3 is a view in perspective showing the unclamped position of thewedge of myA vnovel double throw knife switch.

Figure 4 isa View in -perspectiveshowing the clampedposition of thewedge of my novel knife switch.

Figure 5 is a view corresponding substantially to` that of Figurev lshowing, however, the -handle in the fully closed position.

Figure 6 is a top View partly in cross-section of the wedge memberandits cooperating ele- .ments corresponding to the position shown inFigure 3.

Figure 7 is a View similar to that of Figure 6 with the elementscorresponding; to the View4 of Figure 4.

Referring now to Figures 1 and 2, my novel double throw knife switch .ismounted on an insulating panel I-i to which are connected, the upperstationary contact I2 and the lower staftionary contact i 3. Contacts I2and' I3 are mounted respectively on the ends of` back connection studsI4 and I5, which pass through appropriate openings in the insulatingpanel II The terminal I'I for the movablel contact member is `alsomounted at'the front of th'eein.- sulating panel EIV and is connectedthrough an appropriate opening to its own back conne'c' 'tion stud I8.

The knife blades 2li and 2I which form the movable bridging contact arepivotally mounted Y on the extension 25 of thecontact terminal Il.,

at the extension 25 of the central terminal Plates 28and 29 straddleextension 25 as shown, and are continued up to a point just below thepoint of registry of the handle with the contact member l2 in the upposition or contact member |3 in the down position, at which point theyare re-entrantly bent at 3B, 3| and secured together to form anextension 32 which passes between the jaws of the contact member l2 or|3; A suitable handle 34 is secured to the extension 32.

The side plates 23 and 29 are provided with the registering slots 43through which the pin 4| of the contact blade operating link 42 passes.Contact blade operating link 42 is provided with a cam roller 43 at itslower end which roller may be a compound roller as shown in Figure 2 andits upper end is secured at 44 to the lower end of tension spring 45.

The upper end of tension spring 45 is secured to the pin 46 carriedbetween the handle plates 2B and 29.

` The handle plates 28 and 29 are also provided with the registeringcurved parallel slots t through which passes the sleeve 5I. Sleeve 5| isprovided with a slot 52 at its lower surface and a slightly smallerparallel slot 33 at its upper surface to receive wedge 5l hereinafterdescribed. The contact blade operating link 42 has an opening 55 throughwhich the sleeve 5| also passes.

The opening 55 of the contact operating lever 42 has secured therein inany suitable manner the wedge 51 which, as shown, particularly inFigures 3 and 4, extends from the bottom to the top of opening 55.

The wedge 5l passes through lower slot 52 of sleeve 5| and the upperslot 53 thereof. The slots 52 and 53 are sufliciently wide to permit theWedge to move up and down in the manner hereinafter described.

AS shown also in Figures 2, 3 and 4, and especially in Figures 6 and '7,the sleeve carries therein the split clamping studs 6c and 6|.

Stud 5| is secured by the bolt B3 to clamping plate 64. Stud ii issecured by bolt 55 to clamp- The central extension 25 from the centralterminal is provided with the cam surface iii having the central frontrecess 1|, upper curve 12, and lower curve '|3.

In the neutral or open position of the switch as shown by the dottedlines of Figure l, the cam roller 43 of link 42 is in the central recess'll of the cam Til. Tension spring 45 acts as a centering spring to holdthe handle member 2 in the horizontal position. To further ensure thatthe handle member 2l remains in the horizontal position, the slots 50are provided with the matching recesses 'i5 which register with the lugs16 secured to the tube 5|.

The opening 30 of handle plates 28 and 29 around the center ofrotationof pivot 8| mounted on extension 25 is slightly larger than thepivot 8i. Accordingly, spring 4%3 pulls the handle 2'? to the left inthe horizontal open dotted line position of Figure l so that notches 'l5engage the lugs 'l5 t0 maintain the open position.

When it is desiredto close the switch to the up position of Figure l,the handle 34 is first pulled out pulling out the handle assembly 2? anddisengaging notches i5 from extension it. The manually graspable handle34 and the handle assembly 2l is now raised rotating about the center3|. Since the pin 4I of link 42 is held in the slot 46, motion istransmitted to the link 42 through an appropriate roller on the pin 4|and link 42 is also rotated upwardly. Since, however, roller 43 is heldin the recess il, the upper end of link 42 moves up faster than pin 4|and hence faster than the handle assembly 2'?. This moves the sleeve 5|up faster than the handle assemblly 2 and sleeve 5i moves rapidly towardthe left in the slot 5i) of the handle assembly 2 while the handleassembly is being moved up by hand. This" extends the tension spring andat the same time causes the contact blad-es 2i] and 2| to move up aheadof the handle assembly 2 to contacting position.

The extension of tension spring 45 now exerts a lifting pressure on link42 pulling roller 43 out of the depression l'l and up onto the uppersurface 12 of cam "iii, Spring 45 ensures that roller 43 of lever 42will follow the cam surface.

' When the contact blades 2| engage Contact I2. of the upper terminal,further travel in a counterclockwise or up direction of the handleassembly 21 forces the roll-er 43 to roll along the upper surface of camlil. This forces the link 42 and the wedge 5i in the upper end thereofto rise with respect to the sleeve 5| and the slot 5i).

As the wedge 57| rises, it moves from the position shown in Figures 3and 6 to the position shown in Figures 4 and 7 spreading the re-entrantextensions 68 and |53 of the split clamp studs iii! and 6| apart. Thisdraws together the studs ii and Sl and the bolts 53 and t5 thereof, thusdrav ing together the clamping members 64 and Sii.

When the handle assembly 2'| has reached the full contact closingposition, the wedge 5l has been moved up to the linal position ofFigures 4 and 'l and has as previously described fully drawn togetherthe clamping members 64 and B5, thus clamping the bridging contactblades 23 and v2| tightly across the contact members I2 and 2c.'

The handle 34 is provided with a latch tip 90 which engages the latchkeeper 9| at the upper terminal I2. The spring 45 causes the latchmembers 9G and `9| to interengage.

To open the contacts, handle 34 is rst lifted to disengage latches Siiand 3| extending the spring 45 slightly for this purpose and the handleassembly 2 is then rotated downwardly. IThe reverse of the operationabove described occurs. The initial clockwise rotation of handleassembly 2T owing to the arrangement of slot 4E! and pin 4| causes thelink 42 to rotate to the intermediate position shown at the upperportions of Figure l. This, since it is the reverse of the previousoperation, lowers the wedge from the position of Figures 7 and 4 to theposition of Figures 6 and 3. This releases the clamps 64 and 35; andfurther clockwise rotation of the handle assembly 2'.s moves the switchblades 2i? and 2| and all of the handle elements to the horizontaldotted line position of Figure l.

The operation for engaging the contact blades 20 and 2i across contactsI3 and 25 is exactly the same. The handle assembly 2l vis pulled out andmoved down; the contact blades 20 and 2| first engage the stationarycontact i3 and then the clamp is tightened in exactly the manner abovedescribedwhen the handle assembly 2'. is pushed home to the verticalposition. Latch S2 of the handle 34 vengages the latch keeper 93 tomaintain the lower contact closed position.

By this means, therefore, a simple clampable double throw knife typeswitch is provided with a simplified Wedging element which is actuatedto clamping position both in the up and down closed position of thecontacts. Complex machining or threading operations are avoided and asingle wedge combined with a single split clamping stud arrangement andthe actuation of the wedge by a single cam member performs the clampingoperation in either closed position.

In the foregoing, I have described my invention solely in connectionwith a specific preferred embodiment thereof. Since many variations andmodiiications of my invention should now be obvious to those skilled inthe art, I prefer to be bound not by the specic disclosure hereincontained but only by the appendedclaims.

I claim:

1. In a switch mechanism., a pivotally mounted double throw knife switchblade, a pair of terminals, each of said terminals comprising a pair ofjaws, a handle assembly comprising a pair of side plates pivotallymounted on the same pivot as said blade, a handle secured to said sideplates, a slot in said side plates, a pin mounted in said slot, acontact operating link mounted on said pin, a camming surface, a camfollower on one end of said link and'a spring extending from the otherend of said link to said side plates for maintaining said cam followeron said camming surface, a pair of clamping plates, a supporting meansfor said clamping plates, a wedge operable in said supporting means formoving said supporting means to efect movement of said clamping platestoward and away from each other, means controlled by the movement ofsaid handle for operating said link to drive said cam on its follower;said supporting means being responsive to the movement of said cam foroperating said blade assacs to engage said jaws, and said link meansbeing' thereafter responsive to further movement of said handle fordriving said Wedge to effect axial movement of said supporting means toin turn operate said clamping plates to clamp said jaws to said switchblade.

2'. In a switch mechanism, a pivotally mounted double throw knife switchblade, a pair of terminals each comprising a pair of jaw blades, anoperating handle, a pair of clamping plates, a member for carrying saidclamping plates, a Wedge mounted on said member, means responsive tomovement of said handle for operating said knife blade to engage one ofsaid terminals and for thereafter operating said Wedge to operate saidmember to move said clamping plates and clamp said blade to saidterminal, and means for locking said rst mentioned means in either ofsaid operating positions with said terminals and in an intermediateposition.

ARTHUR S. CASWELL.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 528,900 Bolles Nov. 6, 1894541,608 Hancock June 25, 1895 633,771 Wright et al Sept. 26, 1899691,766 Hewlett Jan. 28, 1902 1,850,771 Raney Mar. 22, 1932 1,889,358Hammerly Nov. 29, 1932 2,095,554 Maseng Oct. 12, 1937 2,234,563 KneassMar. 1l, 1941 2,246,072 Scott, Jr June 17, 1941 2,385,304 Schymik Sept.18, 1945

